An intra-aortic floating metastatic malignancy of unknown primary origin

Abstract

A 69-year-old man with sudden strong back pain was transported to our hospital by ambulance. The computed tomography scan revealed an intra-aortic floating mass with a stalk arising from the descending aortic wall, which was thought to be a thrombus. The floating mass displayed the characteristics of a thrombus rather than a neoplastic tumour on magnetic resonance imaging scan. Under extracorporeal circulation, the descending aorta was cut open, and the mass was resected. Subsequently, a stent graft was placed to cover the abnormal aortic intima to prevent recurrent thrombus formation. The pathological diagnosis revealed an adenocarcinoma, not a thrombus. We could not detect the origin of malignancy despite additional examinations. Brain metastasis developed, and the patient died of recurrent pneumonia and urinary tract infection. These findings emphasize the importance of a precise plan of action for rare diseases.